Question about &filter=0

google filter question

[catch_22]

Can someone tell me if while currently ranked #4 for kw 1 and #3 for kw 2, is it a bad thing to completely disappear when I type &filter=0 at the end of the URL of my search?

I was #1 for my main keyword post Florida, and recently Austin is playing musical chairs with my site. I have gone to #5, #141, #79 and back to #4. In the meantime one of my close competitors does the opposite. If I move to #4, he moves from #4 to #90. And vice versa. What gives?

So, &filter=0 is bumping me out and putting him back in.